# Mid-IR Electromagnetic Topological Edge Modes: Design, Fabrication, and Polarization States Confirmed by High-Angle-Resolution Reflection Spectroscopy

https://mdr.nims.go.jp/datasets/b7e8323c-dbb8-4fb6-80a8-691dee4276b1

## File

- [jpsj.94.101004-2.pdf](https://mdr.nims.go.jp/filesets/b9e32387-ba67-4d3b-8fcc-169533effcb3/download) ([Detail](https://mdr.nims.go.jp/filesets/b9e32387-ba67-4d3b-8fcc-169533effcb3.md))

## Id

b7e8323c-dbb8-4fb6-80a8-691dee4276b1

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2026-01-22T06:00:06.620310Z

## Updated at

2026-02-10T23:30:03.854401Z

## Published at

2026-02-10T09:03:06.440541Z

## Doi



## First published url

https://doi.org/10.7566/jpsj.94.101004

## Date published

2025-10-15

## Recorded date published

2025-10-15

## Resource type

journal_article

## Manuscript type

vor

## Collection



## Title

- title: 'Mid-IR Electromagnetic Topological Edge Modes: Design, Fabrication, and
    Polarization States Confirmed by High-Angle-Resolution Reflection Spectroscopy'
  title_type: original
  lang: en

## Description

- description: We review our recent studies on the design, fabrication, and experimental
    verification by angle-resolved reflection spectroscopy of topological photonic
    crystals (PhCs) and topologically protected edge modes in the mid-infrared frequency
    range. We adopted a sample design based on the symmetry reduction from the honeycomb
    lattice to the C6v-symmetric lattice to tune the frequencies of E1- and E2-symmetric
    eigenmodes on the gamma point of the Brillouin zone. In addition to topologically
    trivial and non-trivial band gaps, we also succeeded in observing double Dirac
    cones with an isotropic linear dispersion relation by accidental degeneracy of
    the E1- and E2-symmetric modes. Our specimens had simple structures of PhC slabs
    fabricated in SOI (silicon-on-insulator) wafers without under-etching of a sacrificial
    layer beneath the PhC. Therefore, the photonic band gaps are generally narrow
    due to the small contrast of refractive indexes. Nevertheless, we achieved a sufficiently
    wide band gap of 6% relative to the midgap frequency, which facilitated our observation
    of the edge modes. We also verified experimentally that the edge modes were linearly
    polarized on the gamma point due to the 1:1 mixture of the original left- and
    right-circular polarizations. All these experimental observations were achieved
    by using our home-made reflection measurement apparatus with a 0.3 degree angle
    resolution.
  description_type: abstract
  lang: und

## Creator

- name: Yuanzhao Yao
  role: author
  orcid: https://orcid.org/0000-0003-2504-2795
- name: Afshan Begum
  role: author
  orcid: https://orcid.org/0000-0002-2384-3719
- name: Naoki Ikeda
  role: author
  orcid: https://orcid.org/0000-0002-9552-7467
- name: Yoshihiko Takeda
  role: author
  orcid: https://orcid.org/0000-0003-4961-3687
- name: Takashi Kuroda
  role: author
  orcid: https://orcid.org/0000-0001-6445-7673
- name: Kazuaki Sakoda
  role: author
  orcid: https://orcid.org/0000-0002-5530-3020

## Contact agent



## Publisher

organization: Physical Society of Japan

## Managing organization



## Keyword

- subject: Mid-IR
  schema: not_defined
- subject: Topological Edge Mode
  schema: not_defined
- subject: Photonic crystals
  schema: not_defined
- subject: High-angle resolution
  schema: not_defined

## Rights

- identifier: https://creativecommons.org/licenses/by/4.0/

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## Embargo



## Journal

- title: Journal of the Physical Society of Japan
  issn: '00319015'
  volume: '94'
  issue: '10'
  article_number: '101004'

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## Fileset

- id: b9e32387-ba67-4d3b-8fcc-169533effcb3
  filename: jpsj.94.101004-2.pdf
  content_type: application/pdf
  size: 10239762
  md5: b01fb25e80363a7ad3069ccf93c654fa

## Thumbnail

fileset_id: b9e32387-ba67-4d3b-8fcc-169533effcb3
filename: jpsj.94.101004-2.pdf